error.cpp

oledb的例子

//---------------------------------------------------------------------------
// Microsoft OLE DB Programmer's Reference Sample
// Copyright (C) 1998 By Microsoft Corporation.
// 
// @doc
// 
// @module ERROR.CPP
//
//---------------------------------------------------------------------------


////////////////////////////////////////////////////////////////////////

// Includes

//

////////////////////////////////////////////////////////////////////////

#include "prsample.h"         // Programmer's Reference Sample includes

////////////////////////////////////////////////////////////////////////
// myHandleResult
//
// This function is called as part of the XCHECK_HR macro; it takes an
// HRESULT, which is returned by the method called in the XCHECK_HR
// macro, and the file and line number where the method call was made.
// If the method call failed, this function attempts to get and display
// the extended error information for the call from the IErrorInfo,
// IErrorRecords, and ISQLErrorInfo interfaces.
//
////////////////////////////////////////////////////////////////////////

HRESULT myHandleResult( HRESULT           hrReturned,
												LPCWSTR           pwszFile,
												ULONG             ulLine)
{
  HRESULT           hr;
	IErrorInfo *      pIErrorInfo      = NULL;
	IErrorRecords *   pIErrorRecords   = NULL;
	ULONG             cRecords;
	ULONG             iErr;

	// If the method called as part of the XCHECK_HR macro failed,
	// we will attempt to get extended error information for the call
	if( FAILED(hrReturned) )
	{

		// Obtain the current error object, if any, by using the
		// Automation GetErrorInfo function, which will give
		// us back an IErrorInfo interface pointer if successful

		hr = GetErrorInfo(0, &pIErrorInfo);

		// We've got the IErrorInfo interface pointer on the error object

		if( SUCCEEDED(hr) && pIErrorInfo )
		{
			// OLE DB extends the Automation error model by allowing
			// error objects to support the IErrorRecords interface. This
			// interface can expose information on multiple errors.
			hr = pIErrorInfo->QueryInterface(IID_IErrorRecords, (void**)&pIErrorRecords);
			if( SUCCEEDED(hr) )
			{
				// Get the count of error records from the object
				CHECK_HR(hr = pIErrorRecords->GetRecordCount(&cRecords));
				// Loop through the set of error records, and
				// display the error information for each one
				for( iErr = 0; iErr < cRecords; iErr++ )
				{
					myDisplayErrorRecord(hrReturned, iErr, pIErrorRecords, pwszFile, ulLine);
				}
			}

			// The object didn't support IErrorRecords; display
			// the error information for this single error
			else
			{
				myDisplayErrorInfo(hrReturned, pIErrorInfo, pwszFile, ulLine);
			}
		}
		// There was no error object, so just display the HRESULT
		// to the user
		else
		{
			wprintf(L"\nNo Error Info posted; HResult: 0x%08x\n"L"File: %s, Line: %d\n", hrReturned, pwszFile, ulLine);
		}
	}

	CLEANUP:

	if( pIErrorInfo )
		pIErrorInfo->Release();

	if( pIErrorRecords )
		pIErrorRecords->Release();

	return hrReturned;

}

////////////////////////////////////////////////////////////////////////
// myDisplayErrorRecord
//
// This function displays the error information for a single error
// record, including information from ISQLErrorInfo, if supported
//
////////////////////////////////////////////////////////////////////////

HRESULT myDisplayErrorRecord(	HRESULT           hrReturned, 
															ULONG             iRecord, 
															IErrorRecords *   pIErrorRecords, 
															LPCWSTR           pwszFile, 
															ULONG             ulLine)
{

	HRESULT           hr;
	IErrorInfo *      pIErrorInfo       = NULL;
	BSTR              bstrDescription   = NULL;
	BSTR              bstrSource        = NULL;
	BSTR              bstrSQLInfo       = NULL;
	static LCID       lcid              = GetUserDefaultLCID();
	LONG              lNativeError      = 0;
	ERRORINFO         ErrorInfo;

	// Get the IErrorInfo interface pointer for this error record
	CHECK_HR(hr = pIErrorRecords->GetErrorInfo(iRecord, lcid, &pIErrorInfo));
	// Get the description of this error
	CHECK_HR(hr = pIErrorInfo->GetDescription(&bstrDescription));
	// Get the source of this error
	CHECK_HR(hr = pIErrorInfo->GetSource(&bstrSource));
	// Get the basic error information for this record
	CHECK_HR(hr = pIErrorRecords->GetBasicErrorInfo(iRecord, &ErrorInfo));
	// If the error object supports ISQLErrorInfo, get this information
	myGetSqlErrorInfo(iRecord, pIErrorRecords, &bstrSQLInfo, &lNativeError);
	
	// Display the error information to the user
	if( bstrSQLInfo )
	{
		wprintf(L"\nErrorRecord: HResult: 0x%08x\nDescription: %s\n"
						L"SQLErrorInfo: %s\nSource: %s\nFile: %s, Line: %d\n", 
						ErrorInfo.hrError, 
						bstrDescription, 
						bstrSQLInfo, 
						bstrSource, 
						pwszFile, 
						ulLine);

	}

	else
	{
		wprintf(L"\nErrorRecord: HResult: 0x%08x\nDescription: %s\n"
						L"Source: %s\nFile: %s, Line: %d\n", 
						ErrorInfo.hrError, 
						bstrDescription, 
						bstrSource, 
						pwszFile, 
						ulLine);

	}

	CLEANUP:

	if( pIErrorInfo )
		pIErrorInfo->Release();

	SysFreeString(bstrDescription);
	SysFreeString(bstrSource);
	SysFreeString(bstrSQLInfo);

	return hr;

}

////////////////////////////////////////////////////////////////////////
// myDisplayErrorInfo
//
// This function displays basic error information for an error object
// that doesn't support the IErrorRecords interface
//
////////////////////////////////////////////////////////////////////////

HRESULT myDisplayErrorInfo(	HRESULT        hrReturned, 
														IErrorInfo *   pIErrorInfo, 
														LPCWSTR        pwszFile, 
														ULONG          ulLine)
{
	HRESULT        hr;
	BSTR           bstrDescription   = NULL;
	BSTR           bstrSource        = NULL;

	// Get the description of the error
	CHECK_HR(hr = pIErrorInfo->GetDescription(&bstrDescription));
	// Get the source of the error -- this will be the window title
	CHECK_HR(hr = pIErrorInfo->GetSource(&bstrSource));
	// Display this error information
	wprintf(L"\nErrorInfo: HResult: 0x%08x, Description: %s\nSource: %s\n"
					L"File: %s, Line: %d\n", 
					hrReturned, 
					bstrDescription, 
					bstrSource, 
					pwszFile, 
					ulLine);

CLEANUP:
	SysFreeString(bstrDescription);
	SysFreeString(bstrSource);

return hr;

}

////////////////////////////////////////////////////////////////////////
// myGetSqlErrorInfo
//
// If the error object supports ISQLErrorInfo, get the SQL error
// string and native error code for this error
//
////////////////////////////////////////////////////////////////////////

HRESULT myGetSqlErrorInfo(ULONG             iRecord, 
													IErrorRecords *   pIErrorRecords, 
													BSTR *            pBstr, 
													LONG *            plNativeError)
{
	HRESULT           hr;
	ISQLErrorInfo *   pISQLErrorInfo   = NULL;
	LONG              lNativeError     = 0;

	// Attempt to get the ISQLErrorInfo interface for this error
	// record through GetCustomErrorObject. Note that ISQLErrorInfo
	// is not mandatory, so failure is acceptable here.
	CHECK_HR(hr = pIErrorRecords->GetCustomErrorObject(
																	iRecord,                               // iRecord
																	IID_ISQLErrorInfo,                     // riid
																	(IUnknown**)&pISQLErrorInfo            // ppISQLErrorInfo
																));
	// If we obtained the ISQLErrorInfo interface, get the SQL
	// error string and native error code for this error
	if( pISQLErrorInfo )
		hr = pISQLErrorInfo->GetSQLInfo(pBstr, &lNativeError);

CLEANUP:
	if( plNativeError )
		*plNativeError = lNativeError;
	if( pISQLErrorInfo )
		pISQLErrorInfo->Release();

	return hr;

}